#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

int main(int argc,char **argv)
{
    int fd;
    if(argc < 2){
        fprintf(stderr,"Usage \n");
        exit(1);
    }
    fd = open(argv[1],O_WRONLY | O_CREAT | O_TRUNC,0600);
    if(fd < 0){
        perror("open()");
        exit(1);
    }
    lseek(fd,5LL*1024LL*1024LL*1024LL-1,SEEK_SET);

    write(fd,"",1);
    close(fd);
    exit(0);
}